compatibility issue regarding the active processor count

[Xiaobin Lu]

Hi folks,

I need your opinion about what we should do to solve the compatibility 
issue regarding the active processor count. Basically, the problem is on 
Solaris, if you create a processor set and then launch java process 
without binding to that processor set, the number of available 
processors to that java process is the total number of the online 
processors minus the number of processors in the processor set you 
created. Currently, we just report the total number of the online 
processors as the active processor count which is wrong. This makes the 
parallel garbage collector to behave in the wrong way (see bug 6749430 
for details) and we need to fix it per request from CBOE.

There may be a compatibility issue after we correct this wrong behavior 
when someone has already depended on this wrong return, which we think 
it might be rare. We definitely need to invent a new flag in order to 
address this and the question is whether we should keep the current 
behavior as default or not. Personally, I feel we should have that flag 
to fall back to the current wrong behavior, but I might be wrong.

Thanks so much in advance for your opinion.

-Xiaobin